Gymnastics rings are one of the most common gymnastics apparatuses in men's gymnastics. A classic gymnastics exercise performable on the rings which requires a great deal of physical strength to perform is known as the "iron cross". Gymnasts in the past have developed the strength, balance and skill necessary to perform the iron cross by rigging pulley systems to real gymnastics ring setups. Other times, gymnasts have rigged pulley systems to another piece of gymnastics apparatus known as the high bar.
FIG. 1 (Prior Art) shows a gymnast 1 practicing the iron cross exercise using such a pulley system rigged to a real gymnastics ring setup. The real gymnastics rings 2 are shown hanging by lines 3 which normally suspend the rings 2 from the ceiling 4 of a gymnasium. Such lines 3 are usually quite long and may have a length of about 20 feet. The pulley assembly which is rigged to the real gymnastics ring setup comprises pulleys 5-8, ropes 9 and 10, rings 11 and 12, and a harness 13. By using the pulley system to support the weight of the gymnast, the gymnast 1 could utilize a mechanical advantage realized by a block and tackle pulley system of the pulley system to power up into and pull out from the iron cross position multiple times until the gymnast 1 had developed the necessary strength, balance and skill to the do the iron cross exercise on the real rings 2 without the aid of pulleys.
Although practicing the iron cross on such a pulley system was possible for an already somewhat accomplished gymnast, a significant amount of control, balance, and strength was required in order to control the setup. The ropes 9 and 10 of the pulley system typically were stretchable under the body weight of the gymnast 1. If more weight was placed on one ring of the pulley system than was placed on the other, one of the ropes 9 or 10 could stretch to be longer than the other rope. The gymnast could therefore find himself trying to learn to hold the iron cross position from uneven rings 11 and 12. In FIG. 1, the rings of the pulley system are shown in such an awkward uneven position with ring 11 being lower than ring 12.
Moreover, the relatively long lines 3 which normally attached the rings 2 of the real gymnastics ring setup to the gymnasium ceiling 4 often began to vibrate under the trembling of the struggling gymnast 1. This vibration often contributed to a loss of balance and control. Accordingly, maintaining balance with uneven and vibrating rings made practicing the iron cross with the pulley system quite difficult in itself. Additional people called "spotters" were therefore often required to prevent the gymnast from swinging and to prevent injury to the gymnast in the event that the gymnast were to lose balance and fall from the pulley system when attempting to learn the iron cross exercise.
Today, in physical exercising and conditioning, there is a general trend away from building large bulky muscles and toward building lean yet strong muscles. High repetition aerobic and semi-aerobic conditioning exercising has therefore become popular in comparison to relatively low repetition power lifting of heavy weights. New exercise machines for the gymnasium, the health club, and the home alike are therefore sought which build lean, attractive strong muscle through relatively high repetition exercising without the need of spotters.